1. Field of the Invention
The present invention relates to packaging substances, including both liquids and substances that are at least semi-liquid or creamy, in a dispenser that possesses a rigid case having an internal flexible bag and fitted with a dispenser member enabling its contents to be expelled in successive measured quantities.
2. Related Technology
Commonly, an outer casing serves as a receptacle and is closed by a dispenser member. The dispenser member comprises a mechanism enclosed in a tubular body having a bottom inlet. The mechanism is controlled by pressing down a hollow rod which projects upwards and that serves as an outlet duct or nozzle. The rod is upwardly biased by a return spring. The dispenser member may be a valve, in which case the substance is expelled by pressure from a propellant gas inserted on initial packaging. Alternatively, the dispenser member may be a pump having an axial piston driven by the nozzle for extracting the desired quantity of substance via suction established by the piston rising in its chamber and then for expelling said quantity to the outside via the force of the descending piston. To bring the pressure inside the receptacle back into equilibrium, the pump possesses a vent which is closed by the piston while in its rest position but is open and allows a limited quantity of air to enter during each use.
However, with such devices, the substance is often not contained directly in the rigid outer casing, but in a flexible bag housed therein. The flexible bag possesses an opening which is connected to the dispenser member, the outer casing merely constituting an outer cover. This disposition serves in particular to protect the quality of the substance during long-duration storage. In particular, when the dispenser member is a pump, it enables the substance to be conserved while it is protected from the air. It also makes it possible to prevent volatile substances from evaporating.
In the most convenient of known structures, the dispenser member and the flexible bag are connected together by a ring-forming bushing which possesses a cylindrical skirt attached to an upper band. The opening of the bag is fixed in a sealed manner to the skirt. At least a portion of the tubular body of the dispenser member penetrates through the band and is in turn secured thereto in a sealed manner.
The bushing advantageously possesses a flange attached to the band for centering and support purposes. After the bag has been inserted in the outer cover, the flange allows the bag to be held in the opening of the cover to allow the substance to be injected therein. Thereafter the dispenser member, a pump in the present case, is installed. The dispenser member can be fixed to the bushing and the assembly can be fixed to the opening of the cover using all sorts of members with various connection means such as screws, two regions of leak-proof mutual engagement, etc.
Finally, even when a pump is used, the dispenser member has no vent. However, to allow the bag to collapse progressively as substance is extracted therefrom by the pump without giving rise to suction in the space left empty between the bag and the cover, this space is connected to the atmosphere via a balancing channel, orifice, or path through the cover or beneath the bushing.